Boost leak from biss scew [Merged 8-8]

[GeneralChaos]

Searched and cant find anything.

When I was performing my leakdown last time a ton of air was coming out of the BISS screw when I sprayed soapy water on it, as well as a part of the gasket.

Is this screw supposed to just unscrew out? or does the throttle body need to be taken apart? We couldnt get it out and I remember reading people replacing an o-ring in there somewhere.

Just trying to get all the materials and knowledge I need for this weekend.

 

[magik95]

Mmm, shiny new OEM parts to fix your leaks...mmmmm.

You can get yourself a new BISS screw set.

Never seen that site! Thanks for that Ill be getting some of that stuff.

 

[98GSXtreme07]

I highly recommend STM for OEM stuff! New BISS kit will help you out sir!

 

[magik95]

So thats 80% chance that the main problem?

 

[98GSXtreme07]

Oh, sorry. I meant that I recommend getting BISS set from them to help you with your old/leaking BISS. Not sure if it will completely fix your problem. Thats step 1 and than go from there. Good luck!

 

[magik95]

Thanks. I think my plan is to go to J-yard and pull another t/b. Im guessing that if the biss just went to crap all of the sudden to cause this problem mt t/b must be shot. Did I mention Im running a n/t t/b?

Another thought is to replace the intake gasket also evne though I didnt get a leak from it.

 

[BoostFrenzy]

Never seen that site! Thanks for that Ill be getting some of that stuff.

Np man. STM is a good company to deal with.

Not sure if it will completely fix your problem. Thats step 1 and than go from there. Good luck!

Exactly. Fix what you know is bad and then it narrows down really fast to what is the problem. Or, you have a really messed up car and it takes forever and a day either way . Good way to think about it is that you will have all the smaller bases covered so they don't seem extreme latter on when/if you become tight on cash. But since you can hear the BISS leaking pretty audible, then it is a good idea to get a new one anyway. Those plastic threads on the screw always like to get messed up if someone has "tinkered" around with it. So with that little replacement kit you get the screw, the O-ring and then the little cap to cover the BISS opening.

 

[heckles]

^^^^^^^^ there fairly cheap so Id get a couple sets. I always forget to put the cap back on before driving off.

 

[DSMboostin15]

The reason that the BISS leaks is that the O-ring under the screw dries out and leaks. A super cheap fix is to just buy the O-ring from the local hardware store. It's a #5 O-ring, about $0.50.
A word of advice, most new O-rings are dry, meaning that they require a little lube to slide in without the possibility of ripping or nicking on the way in and it will help create a better seal.

 

[TOONAH]

Magik95,
You said you are using a Non-Turbo TB right? I am converting NT to Turbo and I am using the NT TB because is has a larger diameter. More air Flow. Anyhow, I read a thread here some time back about
the Throttle plate shaft seals. You must change them out for the metal frame type seal. You have to machine a few thousandths from the seal seats in the TB for the Chicago Rawhide seals to fit perfectly.
I forget the part number. The buggers are $10 each! But they are a known culprit of boost leak in the TB. I did not botherto do the machining of the seats. I gooped them up with dielectric grease and smacked them in with a single short sharp tap using a 8mm socket. A little of the rubber shaved off. but not enough to damage the integrity of the outer part of the seal. Hope this helps.

 

[magik95]

Magik95,
You said you are using a Non-Turbo TB right? I am converting NT to Turbo and I am using the NT TB because is has a larger diameter. More air Flow. Anyhow, I read a thread here some time back about
the Throttle plate shaft seals. You must change them out for the metal frame type seal. You have to machine a few thousandths from the seal seats in the TB for the Chicago Rawhide seals to fit perfectly.
I forget the part number. The buggers are $10 each! But they are a known culprit of boost leak in the TB. I did not botherto do the machining of the seats. I gooped them up with dielectric grease and smacked them in with a single short sharp tap using a 8mm socket. A little of the rubber shaved off. but not enough to damage the integrity of the outer part of the seal. Hope this helps.

Damn! That could be my propblem because I didnt know that about the n/t tb. I changed the biss o ring and the old one was like plastic! I did another bl test and it seems to not have anymore leaks but then again it still could be or rather I think it still is somewhere because it boosted fine for a split second and then started doing the same thing!